CA1180061A - Electrical-optical interface network - Google Patents
Electrical-optical interface networkInfo
- Publication number
- CA1180061A CA1180061A CA000405778A CA405778A CA1180061A CA 1180061 A CA1180061 A CA 1180061A CA 000405778 A CA000405778 A CA 000405778A CA 405778 A CA405778 A CA 405778A CA 1180061 A CA1180061 A CA 1180061A
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- CA
- Canada
- Prior art keywords
- network
- electrical
- circuit
- optical
- signals
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 230000008054 signal transmission Effects 0.000 claims abstract description 3
- 230000003287 optical effect Effects 0.000 claims description 25
- 230000008878 coupling Effects 0.000 claims 2
- 238000010168 coupling process Methods 0.000 claims 2
- 238000005859 coupling reaction Methods 0.000 claims 2
- 238000001514 detection method Methods 0.000 abstract description 4
- 230000005540 biological transmission Effects 0.000 abstract description 3
- 101100172132 Mus musculus Eif3a gene Proteins 0.000 description 2
- 244000228957 Ferula foetida Species 0.000 description 1
- 230000003466 anti-cipated effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 239000013307 optical fiber Substances 0.000 description 1
- 230000002226 simultaneous effect Effects 0.000 description 1
- 230000001702 transmitter Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
- H04L12/40—Bus networks
- H04L12/407—Bus networks with decentralised control
- H04L12/413—Bus networks with decentralised control with random access, e.g. carrier-sense multiple-access with collision detection (CSMA-CD)
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/60—Receivers
- H04B10/66—Non-coherent receivers, e.g. using direct detection
- H04B10/69—Electrical arrangements in the receiver
Abstract
ABSTRACT
ELECTRICAL-OPTICAL INTERFACE NETWORK
An electrical-optical interface network for use in a carrier-sense, multiple-access system with collision-detection provides two-way transmission between an electrical circuit (2) and a pair of lightguides (21,22), and includes a coincidence sensor (34) which prevents signal transmission between the lightguides.
ELECTRICAL-OPTICAL INTERFACE NETWORK
An electrical-optical interface network for use in a carrier-sense, multiple-access system with collision-detection provides two-way transmission between an electrical circuit (2) and a pair of lightguides (21,22), and includes a coincidence sensor (34) which prevents signal transmission between the lightguides.
Description
A. Alban~se 6 ELE~TRICAL~OPT~CAL INTE~FACE NEI'WORK
This invention relates to inter~acing networks for interconnecting electrical circuits and optical links.
Both lightguides and computer networks are readily available and their uses are continuously growing.
It is anticipated that computer networks will b~ne~it by using lightguides a~ the transmission medium bec~use they provide ground loop i~olation, minimize electromagnetic inter~erence~ save space, and provide future cost savings over coaxial cable systems where equalization is required.
While conventional computer networks today do not use lightguide~, their use in future facilities is currently under study. (See the article by E.G, Rawson et al. entitlod "Fibernet: A Fiber Optic Compute~ Network Experiment~, published in the Fourth~ ean ~ on~erenoe a~
. ~lowever, the use Or ~iber links involvos more than simply replacing the coaxial cable with ~ length of optical fiber. ~he optical ~ignal must be detected ~nd converted to an ele¢trioal ~i~nnl and, convorsely~ the electrlcal ~len~l must be convorted to an optlcal ~l~nal. Inasmuoh a~ th~e prooe~se~ nre ~epara~e, the u~e o.e two optioal link~ 1~
~5 r~quired, Furthermore, ln ~ sy~tem e~ploying a ¢ontentlon protoool, tllis must be donfl in a manner whiah p~rmit~ each st~tion to monlto~ all other stations whlle transnl~tting ~o ae to det~ot the presenoe o:~ other interferlng 3ignal~.
,~
3 ~i~ 8~
Simultaneously, the interface network must be capahle o~
avoiding reflections o~ the incident signals~
Acoording to the present invention there is provided an interface network for interfacing between an optical circuit and an electrical circuit comprising receiving means for converting optical signals into electrical signals disposed between a first lightguide in said optical circuit and said electrical circuit, transmitting means for converting electrical signals into op~ical signals disposed between said electrical circuit and a second lightguide, and ~eans, including a coincidence sensor, for preventing the transmission of signals between said lightguides.
In accordance with the invention the coincidence sensor may take the form of an exclusive OR~gate or a Schmidt trigger circuit, Such a network provides simultaneous tr~nsmission between the ~irst lightguide and the electrical circuit, and between th~ latter and the second lightguide, However, tran8mission between the first and second lightguides is precluded.
It is an advantage of the present invention that it permits new network configurations to be used.
Some exe~plary embodiments of the invention will now be de90ribed re~erence being made to the accompanying drawing~, in which:-FI~ how~ a portion o~ Q typical carrier-~ense, multiple-acces~ networlc to wh~ch the invention relates;
F'IG. 2 ~how3 the network portion Oe FIG, 1 in whloh the co~xlal bu~ ha3 been replaaed ~y an Qptioal bu~;
F~G. 3 ~ows ~ :~irst embo~ment of a network ln acc~rdarlce Wi th the pr~sent invention for lnterfaeing hetween the eleatriaal nnd optloal portions o~ the ne-twork of FIG, 2;
FI~. It show~ an alternativo embc)climent o~ an :lnter~ace networ~ in acoordance with thc present invention 38 lnoluding ~n AGC reIresher pul~e sowrce;
FIG. 5 shows a Schmidt trigger circuit; and FIG. 6 shows another network configuration.
Re~erring to the drawings, FIG. 1 shows a portion of a typical carrier-sense, multiple-access communication system with collision-detection (CSMA/~D) where each o~ the station~ (i.e., 5 and 6) is connect~d to a common coa~ial bus 11 by means of a tap 9, 10 an~ a transceiver 7, 8.
Advantageously, the coaxial buses between t~ps are replaced by lightguides in the manner lllu~trated in FIG. 2. In this configuration, the coaxial bus ll is replaced by an optical bus 20 comprising a pair of lightguides 21 and 22 and inter~ace networks 23 and 24. ~Iore specifically, connections to taps 9 and 10 are made by means of the interface networks 23 and 24, respectfully, which interconnect the optical and electrical portions of the networ~. Similarly, other optical buses including interface networks 25 and 26 interface between taps 9 and 10 and other optical lightguides linking portions o~ the rest of the system.
A~ indicated hereinabove, the funcrion of the interface network i~ to provide two-way trallsmi~6ion between the electrlcal and optical circuits wh~le maintaining tha collLsion-detection capability o~ the system, A cirouit configuration ~or dolng this 1~
25 illustrated ln FIG~ 3 which shows~ in block diagram~ the detall~ of An interface network ~nd~ in particular, Ghow~
intarface network 23, A~ illuætrated, ~ach interface network i~ ~ thr~e-port network comprlsing an optical reoeive~ ~1 having ~n optioal lnput port 1 ~nd an 30 electrical nutput port 1~, ~he latter 19 ooupled through a w f~r~k eLectrical sign~ olator ~2~ ~uoh A~ a buf~er a~pl:L:~Ier~ to a common ~l~ctrloal input/oUtput port 2, The .Intter~ ln turn~ i~ ooupled throu~h a second ~l~a~rlcal ~lgnal l~olator 33 ~n~ a coincldence sen~or 3~ (suoh a~ ~n 35 exclll~lve OI~ ke) to the electrlcnl :Lnput port 3~ o:f ~n optic~l kran~mi-ttar 35, ~lore ~poaifically~ one input termlnal of ~onsor 3~) L~ oonnected to the output terminnl 38 of l~olntor 33 wh:lle a 9eoond input t~rmlnal of ~ensor 3 is connected to the output terminal of receiver 31 The interface network is inserted into the CSMA/CD system such that one of the lightguides 21 is connected to optical input port l; the electrical port 2 is connected to tap 9 of the elctrical portion of the sy~tem;
and the second lightguide 22 is connected to the optical output port 3 of transmitter 35.
In operation, optical signals applied to input port 1 are detected by receiver 31 and the resulting electric~l output sign~l is coupled through i901~tor 32 to electrical port 2. The same signal is also coupled through isolator 33 to one input terminal of sensor 34 Simultaneously, the elctrical output from receiver 31 is also coupled to the other input terminal of sensor 34.
Because the two signals applied to the gate are the same, the ~ensor output is zero. Accordingly, the network converts and transmits the received signal between ports 1 and 2, but none of the incident optical signal in lightguide 21 i~ transmitted back along lightguide 22 However, if at the same time an interfering signal i9 present at port 2, the signals applied to the two input terminals of coincidence sensor 34 are no longer balanced, and an output signal 19 coupled to transmitter 35 Thus, the network i~ capable o~ simultaneou~ly tran~mitting in oppo~ite dire¢tions, thereby preserving the collision--detection capability or the ~ystem.
As indieated in FIG, 2, ~ typical optic~l bUB iS
termlnated at both ends by an interface network. Ir ~here 1~ no tra~fic in the bu8~ the AGC circult ln each o~ the ~o n~kworlt reaelvcr~ a~suma~ a maximum galn ~tate whlch would re~ult in overloddin~ of the receiver when traf~io re~u~e~.
~o avold thi~ in ~n ~lternativa embodlment o~ the invention i:llu~trated ln ~lG. l~, Ine~ns are included ill each inter~aoq network eOr re~re~hing thfl AGC of the optlcnl receiver l~o~ted ln the ramote Inter~ca networlc.
A~ lllu~tratcd in ~IG~ ~, the AGC rafresher lnclude~ ~n OR-~at~ nd a pul3e ~ener~or ~2. Using the 38 ~ame identification numerals a~ used ill ~IG. 3 to identify ~8 corresponding components, the OR-gate 41 is located between sensor 34 and transmi-tter 35. The inputs to the OR-gate 41 include -the output signal from sensor 34 and the output signal from pulse generator 42. The OR-gate output is coupled to both transmitter 35 and generator 42, So long as there is tra~fic pre~ent, the O~-gate output inhibits pulse generator ~2 for a prescribed period of time. If there is no traffic, the pulse generator produces pulses of approximately 10 nanoseconds duration in lieu of the normal tra~fic. A filter b~O is shown included in the output circuit o~ optical receiver 31 to remove AGC
refresher pulses generated by a similaI source at a remote interface network (i,e,, 24).
A~ indicated hereinabove, an exclusive OR-gate can be used as the coincidence sensor 34, as also illustrated in FIG. 4. This may require tlie inclusion of a delay circuit ~3, shown in dashed outline, in the path connecting receiver 31 to sensor 34 to compensate ~or the delay~
through the two isolators 32 and ~3. Alternatively, a Schmidt trigger circuit can be employed in place of the OR-gate. FI&. 5 shows a Texas Instruments No. 75115 IC
connected a~ a Schmidt trigger for this purpose. In operation 7 the output goes high only when port 2 goes high and the receiver output goes low.
It should be noted that as a result of the operation of the interface networlc~ the signal transmitted between ports 2 and 3 may be dlstorted if a ~ignal i~ being si~ulta~eously tr~nsmitted between ports 2 and 3~ This, however~ i~ not a problem :ln that it represent~ a collision ~ltuation in whlch caso botll si~nals will have to be retr~n~mittcd, All that ls reqllired i8 that the ~yst~m bo o~p~bl~ of ~en~lng a colllsion con~ ion, ~ 9 in(llcated heroinabove~ it 19 an advaataee of -the pr~s~nt lnven-tloll th~t it pernlit~ new network oon~l~ur~tl~n~ or ~x~lnplc, an ~ leotrl~al network wa~ connectod in a star conrlguratlon~ the impedance mismatch at thc commo~l Junction could producc slgnal rerlection~ that ~Yould improperly indioate a calli~lon ~ 6 situation. IIowever, because o~ the ability of the interface network to prevent the back transmission of the incident signal~ false collision indications are avoided.
~hus, for example, a star networl~ configuration of the type shown in FIG 6 is possihle. In -this illustrative network, a first plurality of stations 58, 60, and 61 are connected to a common junction 69 by means ol a ~.irst plurality of optical buses 59, 64, and 65~ Similarly, a second plurality of stations 62 and 63 are connected to a second common junction 70 by means of a second plurality o~ optical buses 67 and 6a. The common junctions 69 and 70 are, in turn, connected by means of an additional optical bus 66.
Each bus comprises, as illustrated in FIG. 2, a pair o~
lightguides terminated at each end by an optical-to-electrical interface network o~ the type illu~trated inFIGS, 3 and 4.
~0 ~5
This invention relates to inter~acing networks for interconnecting electrical circuits and optical links.
Both lightguides and computer networks are readily available and their uses are continuously growing.
It is anticipated that computer networks will b~ne~it by using lightguides a~ the transmission medium bec~use they provide ground loop i~olation, minimize electromagnetic inter~erence~ save space, and provide future cost savings over coaxial cable systems where equalization is required.
While conventional computer networks today do not use lightguide~, their use in future facilities is currently under study. (See the article by E.G, Rawson et al. entitlod "Fibernet: A Fiber Optic Compute~ Network Experiment~, published in the Fourth~ ean ~ on~erenoe a~
. ~lowever, the use Or ~iber links involvos more than simply replacing the coaxial cable with ~ length of optical fiber. ~he optical ~ignal must be detected ~nd converted to an ele¢trioal ~i~nnl and, convorsely~ the electrlcal ~len~l must be convorted to an optlcal ~l~nal. Inasmuoh a~ th~e prooe~se~ nre ~epara~e, the u~e o.e two optioal link~ 1~
~5 r~quired, Furthermore, ln ~ sy~tem e~ploying a ¢ontentlon protoool, tllis must be donfl in a manner whiah p~rmit~ each st~tion to monlto~ all other stations whlle transnl~tting ~o ae to det~ot the presenoe o:~ other interferlng 3ignal~.
,~
3 ~i~ 8~
Simultaneously, the interface network must be capahle o~
avoiding reflections o~ the incident signals~
Acoording to the present invention there is provided an interface network for interfacing between an optical circuit and an electrical circuit comprising receiving means for converting optical signals into electrical signals disposed between a first lightguide in said optical circuit and said electrical circuit, transmitting means for converting electrical signals into op~ical signals disposed between said electrical circuit and a second lightguide, and ~eans, including a coincidence sensor, for preventing the transmission of signals between said lightguides.
In accordance with the invention the coincidence sensor may take the form of an exclusive OR~gate or a Schmidt trigger circuit, Such a network provides simultaneous tr~nsmission between the ~irst lightguide and the electrical circuit, and between th~ latter and the second lightguide, However, tran8mission between the first and second lightguides is precluded.
It is an advantage of the present invention that it permits new network configurations to be used.
Some exe~plary embodiments of the invention will now be de90ribed re~erence being made to the accompanying drawing~, in which:-FI~ how~ a portion o~ Q typical carrier-~ense, multiple-acces~ networlc to wh~ch the invention relates;
F'IG. 2 ~how3 the network portion Oe FIG, 1 in whloh the co~xlal bu~ ha3 been replaaed ~y an Qptioal bu~;
F~G. 3 ~ows ~ :~irst embo~ment of a network ln acc~rdarlce Wi th the pr~sent invention for lnterfaeing hetween the eleatriaal nnd optloal portions o~ the ne-twork of FIG, 2;
FI~. It show~ an alternativo embc)climent o~ an :lnter~ace networ~ in acoordance with thc present invention 38 lnoluding ~n AGC reIresher pul~e sowrce;
FIG. 5 shows a Schmidt trigger circuit; and FIG. 6 shows another network configuration.
Re~erring to the drawings, FIG. 1 shows a portion of a typical carrier-sense, multiple-access communication system with collision-detection (CSMA/~D) where each o~ the station~ (i.e., 5 and 6) is connect~d to a common coa~ial bus 11 by means of a tap 9, 10 an~ a transceiver 7, 8.
Advantageously, the coaxial buses between t~ps are replaced by lightguides in the manner lllu~trated in FIG. 2. In this configuration, the coaxial bus ll is replaced by an optical bus 20 comprising a pair of lightguides 21 and 22 and inter~ace networks 23 and 24. ~Iore specifically, connections to taps 9 and 10 are made by means of the interface networks 23 and 24, respectfully, which interconnect the optical and electrical portions of the networ~. Similarly, other optical buses including interface networks 25 and 26 interface between taps 9 and 10 and other optical lightguides linking portions o~ the rest of the system.
A~ indicated hereinabove, the funcrion of the interface network i~ to provide two-way trallsmi~6ion between the electrlcal and optical circuits wh~le maintaining tha collLsion-detection capability o~ the system, A cirouit configuration ~or dolng this 1~
25 illustrated ln FIG~ 3 which shows~ in block diagram~ the detall~ of An interface network ~nd~ in particular, Ghow~
intarface network 23, A~ illuætrated, ~ach interface network i~ ~ thr~e-port network comprlsing an optical reoeive~ ~1 having ~n optioal lnput port 1 ~nd an 30 electrical nutput port 1~, ~he latter 19 ooupled through a w f~r~k eLectrical sign~ olator ~2~ ~uoh A~ a buf~er a~pl:L:~Ier~ to a common ~l~ctrloal input/oUtput port 2, The .Intter~ ln turn~ i~ ooupled throu~h a second ~l~a~rlcal ~lgnal l~olator 33 ~n~ a coincldence sen~or 3~ (suoh a~ ~n 35 exclll~lve OI~ ke) to the electrlcnl :Lnput port 3~ o:f ~n optic~l kran~mi-ttar 35, ~lore ~poaifically~ one input termlnal of ~onsor 3~) L~ oonnected to the output terminnl 38 of l~olntor 33 wh:lle a 9eoond input t~rmlnal of ~ensor 3 is connected to the output terminal of receiver 31 The interface network is inserted into the CSMA/CD system such that one of the lightguides 21 is connected to optical input port l; the electrical port 2 is connected to tap 9 of the elctrical portion of the sy~tem;
and the second lightguide 22 is connected to the optical output port 3 of transmitter 35.
In operation, optical signals applied to input port 1 are detected by receiver 31 and the resulting electric~l output sign~l is coupled through i901~tor 32 to electrical port 2. The same signal is also coupled through isolator 33 to one input terminal of sensor 34 Simultaneously, the elctrical output from receiver 31 is also coupled to the other input terminal of sensor 34.
Because the two signals applied to the gate are the same, the ~ensor output is zero. Accordingly, the network converts and transmits the received signal between ports 1 and 2, but none of the incident optical signal in lightguide 21 i~ transmitted back along lightguide 22 However, if at the same time an interfering signal i9 present at port 2, the signals applied to the two input terminals of coincidence sensor 34 are no longer balanced, and an output signal 19 coupled to transmitter 35 Thus, the network i~ capable o~ simultaneou~ly tran~mitting in oppo~ite dire¢tions, thereby preserving the collision--detection capability or the ~ystem.
As indieated in FIG, 2, ~ typical optic~l bUB iS
termlnated at both ends by an interface network. Ir ~here 1~ no tra~fic in the bu8~ the AGC circult ln each o~ the ~o n~kworlt reaelvcr~ a~suma~ a maximum galn ~tate whlch would re~ult in overloddin~ of the receiver when traf~io re~u~e~.
~o avold thi~ in ~n ~lternativa embodlment o~ the invention i:llu~trated ln ~lG. l~, Ine~ns are included ill each inter~aoq network eOr re~re~hing thfl AGC of the optlcnl receiver l~o~ted ln the ramote Inter~ca networlc.
A~ lllu~tratcd in ~IG~ ~, the AGC rafresher lnclude~ ~n OR-~at~ nd a pul3e ~ener~or ~2. Using the 38 ~ame identification numerals a~ used ill ~IG. 3 to identify ~8 corresponding components, the OR-gate 41 is located between sensor 34 and transmi-tter 35. The inputs to the OR-gate 41 include -the output signal from sensor 34 and the output signal from pulse generator 42. The OR-gate output is coupled to both transmitter 35 and generator 42, So long as there is tra~fic pre~ent, the O~-gate output inhibits pulse generator ~2 for a prescribed period of time. If there is no traffic, the pulse generator produces pulses of approximately 10 nanoseconds duration in lieu of the normal tra~fic. A filter b~O is shown included in the output circuit o~ optical receiver 31 to remove AGC
refresher pulses generated by a similaI source at a remote interface network (i,e,, 24).
A~ indicated hereinabove, an exclusive OR-gate can be used as the coincidence sensor 34, as also illustrated in FIG. 4. This may require tlie inclusion of a delay circuit ~3, shown in dashed outline, in the path connecting receiver 31 to sensor 34 to compensate ~or the delay~
through the two isolators 32 and ~3. Alternatively, a Schmidt trigger circuit can be employed in place of the OR-gate. FI&. 5 shows a Texas Instruments No. 75115 IC
connected a~ a Schmidt trigger for this purpose. In operation 7 the output goes high only when port 2 goes high and the receiver output goes low.
It should be noted that as a result of the operation of the interface networlc~ the signal transmitted between ports 2 and 3 may be dlstorted if a ~ignal i~ being si~ulta~eously tr~nsmitted between ports 2 and 3~ This, however~ i~ not a problem :ln that it represent~ a collision ~ltuation in whlch caso botll si~nals will have to be retr~n~mittcd, All that ls reqllired i8 that the ~yst~m bo o~p~bl~ of ~en~lng a colllsion con~ ion, ~ 9 in(llcated heroinabove~ it 19 an advaataee of -the pr~s~nt lnven-tloll th~t it pernlit~ new network oon~l~ur~tl~n~ or ~x~lnplc, an ~ leotrl~al network wa~ connectod in a star conrlguratlon~ the impedance mismatch at thc commo~l Junction could producc slgnal rerlection~ that ~Yould improperly indioate a calli~lon ~ 6 situation. IIowever, because o~ the ability of the interface network to prevent the back transmission of the incident signal~ false collision indications are avoided.
~hus, for example, a star networl~ configuration of the type shown in FIG 6 is possihle. In -this illustrative network, a first plurality of stations 58, 60, and 61 are connected to a common junction 69 by means ol a ~.irst plurality of optical buses 59, 64, and 65~ Similarly, a second plurality of stations 62 and 63 are connected to a second common junction 70 by means of a second plurality o~ optical buses 67 and 6a. The common junctions 69 and 70 are, in turn, connected by means of an additional optical bus 66.
Each bus comprises, as illustrated in FIG. 2, a pair o~
lightguides terminated at each end by an optical-to-electrical interface network o~ the type illu~trated inFIGS, 3 and 4.
~0 ~5
Claims (7)
1. An interface network for interfacing between an optical circuit and an electrical circuit comprising receiving means for converting optical signals into electrical signals disposed between a first lightguide in said optical circuit and said electrical circuit, trans-mitting means for converting electrical signals into optical signals disposed between said electrical circuit and a second lightguide, and means, including a coincidence sensor, for preventing the transmission of signals between said lighguides.
2. A network as claimed in claim 1, in which said coincidence sensor comprises an exclusive OR-gate.
3. A network as claimed in claim 1, in which said coincidence sensor comprises a Schmidt trigger circuit.
4. A network as claimed in claim 2 or claim 3, in which said coincidence sensor includes one input terminal coupled to an output port of said receiving means, a second input terminal coupled to said electrical circuit, and an output terminal coupled to the input port of said transmitting means.
5. A network as claimed in claim 1, 2 or 3, including an AGC refreshing circuit for injecting pulses into said optical circuit in the absence of a signal.
6. A network as claimed in claim 1, 2 or 3, comprising a first electrical signal isolator, for coupling an output port of said receiver means to said electrical circuit, and a second electrical signal isolator for coupling said electrical circuit to an input terminal of said coincidence sensor.
7. A network comprising a plurality of stations and means, comprising an optical bus for connecting each of said stations to a common junction, each of said buses comprising a pair of lightguides terminated at each end by means of an interface network in accordance with claim 1, 2 or 3.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/283,434 US4422179A (en) | 1981-07-15 | 1981-07-15 | Electrical-optical interface network |
| US283,434 | 1981-07-15 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1180061A true CA1180061A (en) | 1984-12-27 |
Family
ID=23086052
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000405778A Expired CA1180061A (en) | 1981-07-15 | 1982-06-23 | Electrical-optical interface network |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US4422179A (en) |
| JP (1) | JPS5819044A (en) |
| CA (1) | CA1180061A (en) |
| DE (1) | DE3225773A1 (en) |
| FR (1) | FR2509935A1 (en) |
| GB (1) | GB2105133B (en) |
| NL (1) | NL191548C (en) |
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| DE3123448A1 (en) * | 1981-06-12 | 1982-12-30 | Siemens AG, 1000 Berlin und 8000 München | ARRANGEMENT FOR CONTROLLING THE BUS ACCESS OF A VARIETY OF DEVICES USING A BUS IN A NETWORK CONSTRUCTED WITH AT LEAST ONE OPTICAL MIXER AS A PASSIVE BUS SYSTEM, ESPECIALLY FOR MULTIPLE COMPUTER SYSTEMS |
| JPS5916453B2 (en) * | 1981-12-03 | 1984-04-16 | 株式会社リコー | Optical data communication system |
| JPS5966243A (en) * | 1982-10-08 | 1984-04-14 | Hitachi Ltd | Data communication system |
| CA1225121A (en) * | 1982-11-05 | 1987-08-04 | Motomu Mochizuki | Optical network system of bus architecture capable of rapidly detecting collision at each communication station |
| DE3246301A1 (en) * | 1982-12-14 | 1984-06-14 | Siemens AG, 1000 Berlin und 8000 München | METHOD FOR DETECTING DATA COLLISIONS IN AN OPTICAL DATA BUS |
| JPS59165537A (en) * | 1983-03-10 | 1984-09-18 | Nec Corp | Light star repeater |
| US4580872A (en) * | 1983-08-17 | 1986-04-08 | Fiberlan, Inc. | Collision detection apparatus utilizing tap means connected to each transmitting optical fiber for fiber optic Local Area Networks |
| DE3622824A1 (en) * | 1986-07-08 | 1988-01-21 | Kloeckner Moeller Elektrizit | Method for data communication between two or more interconnected microprocessor systems and the circuit arrangement for carrying out the method |
| US4850042A (en) * | 1987-04-14 | 1989-07-18 | Westinghouse Electric Corp. | Dual media local area network interfacing |
| DD300214A7 (en) * | 1989-11-02 | 1992-05-27 | Univ Dresden Tech | Transmitting and receiving circuit for local computer networks with collision detection |
| US5325376A (en) * | 1990-02-23 | 1994-06-28 | Canon Kabushiki Kaisha | Communication system for detecting a communication error in information transmitted between a plurality of units and a main control unit |
| US5285449A (en) * | 1991-04-03 | 1994-02-08 | International Business Machines Corporation | Protocol for hybrid local area networks |
| US5222795A (en) * | 1991-12-26 | 1993-06-29 | Light Sciences, Inc. | Controlled light extraction from light guides and fibers |
| US5485465A (en) * | 1992-05-20 | 1996-01-16 | The Whitaker Corporation | Redundancy control for a broadcast data transmission system |
| US5982514A (en) * | 1994-07-11 | 1999-11-09 | Fuji Electric Co., Ltd. | Optical-signal/electric-signal converting device |
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|---|---|---|---|---|
| CH559990A5 (en) * | 1973-06-12 | 1975-03-14 | Patelhold Patentverwertung | |
| DE2458914A1 (en) * | 1974-12-12 | 1976-06-16 | Siemens Ag | Light barrier with transmitter receiver and clock pulse generator - has generator separated from transmitter through safety zone |
| US4063220A (en) * | 1975-03-31 | 1977-12-13 | Xerox Corporation | Multipoint data communication system with collision detection |
| US3991287A (en) * | 1975-04-24 | 1976-11-09 | Bell Telephone Laboratories, Incorporated | Digital echo suppressor noise insertion |
| JPS5259502A (en) * | 1975-11-11 | 1977-05-17 | Nec Corp | Data transmission system using light fiber cable data highway |
| DE2619391C3 (en) * | 1976-04-30 | 1978-11-30 | Siemens Ag, 1000 Berlin Und 8000 Muenchen | Message system with multiple access and decentralized switching |
| JPS6028421B2 (en) * | 1976-12-29 | 1985-07-04 | 富士通株式会社 | Optical transmission branching method |
| US4234970A (en) * | 1977-11-03 | 1980-11-18 | Elliott Brothers (London) Limited | Fiber optic communication system |
| US4271536A (en) * | 1978-10-30 | 1981-06-02 | Bell Telephone Laboratories, Incorporated | Discriminator threshold level control circuit for a digital transmission system |
| US4233589A (en) * | 1979-05-25 | 1980-11-11 | Xerox Corporation | Active T-coupler for fiber optic local networks which permits collision detection |
| JPS598100B2 (en) * | 1979-10-17 | 1984-02-22 | 横河電機株式会社 | Optical data bus system |
-
1981
- 1981-07-15 US US06/283,434 patent/US4422179A/en not_active Expired - Lifetime
-
1982
- 1982-06-23 CA CA000405778A patent/CA1180061A/en not_active Expired
- 1982-07-08 FR FR8212015A patent/FR2509935A1/en active Granted
- 1982-07-09 DE DE19823225773 patent/DE3225773A1/en active Granted
- 1982-07-14 GB GB08220427A patent/GB2105133B/en not_active Expired
- 1982-07-14 NL NL8202852A patent/NL191548C/en not_active IP Right Cessation
- 1982-07-15 JP JP57122253A patent/JPS5819044A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| NL191548B (en) | 1995-05-01 |
| NL191548C (en) | 1995-09-04 |
| JPH0259664B2 (en) | 1990-12-13 |
| GB2105133B (en) | 1985-03-20 |
| JPS5819044A (en) | 1983-02-03 |
| NL8202852A (en) | 1983-02-01 |
| FR2509935B1 (en) | 1985-01-18 |
| GB2105133A (en) | 1983-03-16 |
| DE3225773A1 (en) | 1983-02-03 |
| US4422179A (en) | 1983-12-20 |
| FR2509935A1 (en) | 1983-01-21 |
| DE3225773C2 (en) | 1987-09-17 |
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| MKEC | Expiry (correction) | ||
| MKEX | Expiry |